Ricoh Company, Ltd.

Magane Aoki

Kohji Sakai

Seizo Suzuki

Hiromichi Atsuumi

Yoshinori Hayashi

Hiroyuki Suhara

Takao Yamaguchi

Takeshi Ueda

Kenichi Takanashi

Tatsuya Ito

Satoru Itoh

Koji Hirakura

Taira Kouchiwa

Shigeyoshi Misawa

Tami Isobe

Kiyoshi Yokomori

Syunsuke Fujita

Hiroyoshi Funato

Tomoya Ohsugi

Yoshinobu Nakayama

Naoto Watanabe

Tomohiro Nakajima

Masaaki Ishida

Atsushi Kawamura

Atsufumi Omori

Naoki Miyatake

Satoshi Tsuchiya

Kensuke Masuda

Yasuhiro Nihei

Yukio Itami

Nobuo Sakuma

Akihisa Itabashi

Nobuaki Kubo

Akira Kojima

Kobji Sakai

An optical scanning device includes an optical housing in which a polygon mirror that is rotated by a motor is accommodated and an air inlet that includes a filter. An airflow guiding member is arranged at a position opposite to a surface of the polygon mirror on the air inlet side. An air inducing path is provided, which includes a first flowing path and a second flowing path. The first flowing path includes a first end linked to the air inlet and a second end arranged close to a mirror surface of the polygon mirror. The second flowing path is formed with a surface of the airflow guiding member on an opposite side of the air inlet and a top surface of the polygon mirror.

Optical scanning device and image forming apparatus

A multi-beam optical scanner, in which a lateral magnification &#x3b2; in a composite system of an optical system between the light source for a multi-beam and the scanned surface satisfies the condition: 2&#x3c;&#x3b2;&#x2266;8.5, and a plurality of light spots on the scanned surface execute optical scanning of the scanning lines adjacent to each other.

Multi-beam optical scanner

An optical scanning apparatus includes mechanisms for light modulation, light imaging, light deflecting, and light scanning. The light modulation mechanism includes at least one light modulation device including light modulation elements, and is configured to emit modulated light. The light modulation elements are arranged in a single-dimension formation in a first direction orthogonal to a light axis of the modulated light. The light imaging mechanism transfers the modulated light as light of an object to form an image of the object on an image screen. The light deflecting mechanism deflects the light of the object in a direction orthogonal to the first direction and the axis of the light. The light scanning mechanism is disposed on a passage of the deflected light to scan that light.

Method and apparatus for optical scanning capable of efficiently reducing an image surface distortion

An optical scan device having an optical deflector reflecting a light beam from a light beam source so as to deflect the light beam and having a surface to be scanned on which information is written such that the light beam deflected by the deflector scans the surface is disclosed. Optical detectors are arranged at least in two locations, a start side of writing and an end side of writing, which locations are outside an effective writing area. A measuring part measures a scan time required by the light beam deflected by the optical deflector to scan a range between the optical detectors. A correcting part corrects each dot position of image data in the effective writing area to an arbitrary position based on a variation amount of the measured scan time.

Image forming method, image forming apparatus, optical scan device, and image forming apparatus using the same

A scanning optical system condensing a beam deflected by an optical deflector so as to form a beam spot on a surface to be scanned, comprises two lenses. A lens on the side of optical deflector has a negative refracting power in sub-scanning direction. A lens on the side of surface to be scanned has a positive refracting power in the sub-scanning direction. At least one lens surface of the lens surfaces of the two lenses is such that a shape in a sub-scanning section thereof is a non-arc shape.

Scanning optical system, optical scanning device and image forming apparatus

An optical scanning lens is used in a scanning and image forming optical system which gathers a light flux deflected by a light deflector in the vicinity of a surface to be scanned. The lens is formed by plastic molding of polyolefin resin, and the following condition is satisfied: 0&#x3c;|&#x394;n(x)&#x2212;min[&#x394;n(x)]|&#x3c;34&#xd7;10, where &#x394;n(x) denotes a refractive-index distribution existing inside the lens, in a range which the light flux passes through, in the lens, and min[&#x394;n(x)] denotes the minimum value of the &#x394;n(x).

Optical scanning lens, optical scanning device and image forming apparatus

A multi-beam optical scanning apparatus includes a semiconductor laser array slanted relative to a sub-scanning direction and emitting a plurality of optical beams; a coupling lens converting a shape of each optical beam emitted from the semiconductor laser array; and an aperture with an opening having a size of A&#xd7;A, arranged after the coupling lens in a direction in which the optical beam progresses, where Ais a dimension of the opening in a main scanning direction and Ais a dimension of the opening in the sub-scanning direction. When a length in the main scanning direction of a contour line defined by 1/estrength of a maximum strength of an optical beam at the position of the aperture is L, and a length in the sub-scanning direction of the contour line defined by 1/estrength of the maximum strength of the optical beam at the position of the aperture is L, the following conditional expressions are satisfied:A&#x3c;L, and&#x2003;&#x2003;(1)&#xd7;0.3&#x3c;&#xd7;1.7.&#x2003;&#x2003;(2)

Multi-beam optical scanning apparatus and image forming apparatus

An optical scanner which performs optical scanning of a surface to be scanned by deflecting a luminous flux having a wavelength &#x3bb; from a light source by means of an optical deflector, and condensing the deflected flux toward the surface to be scanned through a scanning image forming optical system, thereby forming an optical spot on the surface to be scanned. The scanning image forming optical system has at least one lens, and when the focal length f&#x3c3; in the main scanning direction at a surface accuracy &#x3c3;i is defined as follows: f&#x3c3;={2.6846 &#x3bb;&#xd7;&#x221a;(k)&#xd7;fm/&#x3c9;}&#x2212;fm where, fm represents the focal length in the main scanning direction of the scanning image forming optical system; k represents the number of lens surfaces; &#x3c9; represents the aimed spot diameter of the optical spot in the main scanning direction at an image height of 0; &#x3c3;I represents the surface accuracy of the i-th lens surface as counted from the optical deflector side; n represents the refractive index of material of the lens having the i-th lens surface; and 1/l represents the spatial frequency in the main scanning direction on the lens surface; then, the surface accuracy &#x3c3;i, the focal length f&#x3c3;, the refractive index n, and the spatial frequency 1/L satisfy, for each lens surface, the following condition: &#x2003;0&#x3c;log &#x3c3;&#x3c;&#x2212;2 log (1/)+log [1/{32&#x3c3;(&#x2212;1)}].&#x2003;&#x2003;(1)

Optical scanner, optical scanning method, scanning image forming optical system, optical scanning lens and image forming apparatus

A multi-beam scanning method for scanning a scanning surface with a plurality of beams which are formed into a plurality of beam spots separated from each other in a sub scanning direction includes providing n number of semiconductor laser array units, each of the n number of semiconductor laser array units having m number of light emitting points, where n is not equal to 1 and m is not equal to 1, coupling light beams emitted from the light emitting points of the semiconductor laser arrays, synthesizing the coupled beams with a beam synthesizing device to obtain m&#xd7;n number of beams and deflecting the m&#xd7;n number of beams at substantially the same time such that the deflected beams are impinged on the scanning surface.

Multi-beam scanning method, apparatus and multi-beam light source device achieving improved scanning line pitch using large light emitting points interval

An optical scanning lens which is used in a scanning and age forming optical system which gathers a light flux deflected by a light deflector in the vicinity of a surface to be scanned. The lens is formed by plastic molding of polyolefin resin, and the following condition is satisfied: 0&#x3c;|&#x394;n(x)&#x2212;min[&#x394;n(x)]|&#x3c;34&#xd7;10, where &#x394;n(x) denotes a refractive-index distribution existing inside the lens, in a range which the light flux passes through, in the lens, and min[&#x394;n(x)] denotes the minimum value of the &#x394;n(x).

A light source emitting a light flux; a coupling optical system couples the light flux from the light source to a subsequent optical system by transforming it into a parallel light flux, an approximately convergent light flux or an approximately divergent light flux; a light deflector reflects the light flux from the coupling optical system with a deflection reflective surface, and deflects it; a scanning and imaging optical system condenses the deflected light flux from the light deflector onto a surface to be scanned as a beam spot; and a correcting optical system is provided for self correcting shift of focal position of the beam spot on the surface to be scanned occurring due to environmental change or the like. The correcting optical system comprises at least one pair of a resin-made lens having an anamorphic surface having a negative power in each of main scanning direction and sub-scanning direction and a glass-made lens having an anamorphic surface having a positive power at least in sub-scanning direction, and is disposed between the coupling optical system and deflection reflective surface.

Optical scanning device, line-image forming optical system therein, imaging adjustment method in the device and image forming apparatus

An optical scanning lens is used in a scanning and image forming optical system which gathers a light flux deflected by a light deflector in the vicinity of a surface to be scanned. The lens is formed by plastic molding of polyolefin resin, and the following condition is satisfied: 0<&verbar;&Dgr;n(x)&minus;min&lsqb;&Dgr;n(x)&rsqb;&verbar;<34&times;10 , where &Dgr;n(x) denotes a refractive-index distribution existing inside the lens, in a range which the light flux passes through, in the lens, and min&lsqb;&Dgr;n(x)&rsqb; denotes the minimum value of the &Dgr;n(x).

A scanning and imaging lens condensing a light flux deflected by a deflector onto a surface to be scanned as a beam spot, has a plurality of lenses. A shape in main scanning cross section of each of both surfaces of a lens on a side of deflector has a convex shape, and a shape in main scanning cross section of at least one surface of the lens on the side of deflector is a non-arc shape. A shape in main scanning cross section of a first surface of a lens on a side of surface to be scanned has a convex shape, and a shape in main scanning cross section of at least one surface of the lens on the side of surface to be scanned is a non-arc shape. The scanning and imaging lens has at least two special toroidal surfaces in each of which a curvature in sub-scanning cross section varies in main scanning direction.

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Kanagawa, Japan

Magane Aoki